This invention relates to a system for treating fluid streams. More particularly, but not by way of limitation, this invention relates to a system and method for separating solids from a fluid stream.
In industrial applications, a fluid stream may contain solids. The solids may be suspended in solution. The particle sizes may range from larger diameter solids to extremely small diameter solids. As those of ordinary skill in the art will recognize, it is desirable to separate the solids from the fluid. For instance, environmental regulations may require that operators separate the solids from a slurry. Additionally, the operator may wish to reuse the base fluid, and hence, the fluid must be purged of solids.
As an example in the drilling industry, the well being drilled contains cuttings from the subterranean well bore. The fluid being used to drill the well is an expensive, chemically enhanced fluid. Therefore, operators wish to salvage the base fluid for reuse.
Regardless of the specific application, there is a need for a system and method to separate solids from fluid streams. Prior art devices suffer from many deficiencies. Prior art systems do not allow for adequate separation of solids from the fluid. The present systems are not packaged in an efficient and well-organized manner. The prior art systems are bulky and can""t be transported from site to site in a single package. The present invention allows the packaging of the system on a frame that can be integrated with a trailer allowing for portability and mobility. Therefore, there is a need for a system and method to efficiently handle and separate solids from a fluid stream. There is also a need to add bulk materials to a recently separated fluid stream. These needs, as well as many other needs, will be met by the novel invention herein disclosed.
A system for separating solids from a fluid stream is disclosed. The system comprises a first shaker adapted to a container, and a settling tank positioned to receive the liquid discharged from the first shaker. The system will also include a first baffle module positioned at the output of the settling tank, with the first baffle module having a discharge opening. The fluid stream proceeds through the container in a first direction. A spiral blade is positioned at the bottom of the container, with the spiral blade adapted to convey the solids in a second direction. The spiral blade will have a controller member that varies the speed of rotation of the spiral blade.
A first pump member is provided, with the first pump member receiving the solids from the spiral blade, along with a first cyclone device that receives the discharge from the first pump member outlet and delivers a separated fluid stream to the initial settling compartment. The solids are discharged to a linear shaker. The linear shaker discharges the separated fluid back into baffle plate module via the open top of the container. In the preferred embodiment, the first baffle module comprises a plurality of baffle plates titled at an angle between 45 degrees to 70 degrees.
Additionally, the system may contain a second pump member that has an input line operatively associated to the bottom of the container to receive the solids and an output line operatively associated with a second tandem cyclone device and linear shaker. The liquid output from the cyclone device is channeled to the initial settling compartment and the solids output from the cyclone device is channeled to the screen of the linear shaker. The collected solids from the screen of the linear shaker is collected to a bin and the fluid falls through the screen and into the baffle plate module.
The system may also comprise a first weir positioned at the first baffle module and a second baffle module positioned adjacent the first baffle module. Additionally, the container may include a mixing compartment operatively connected to the discharge line from the baffle plate modules, the mixing compartment having a hopper and a mixing blade disposed therein. In the preferred embodiment, the container is mounted to a base frame having a set of wheels for mobile transportation. A pump member is operatively associated with the mixing compartment, with the pump member having a suction line from within the mixing container and a discharge line within the mixing compartment.
A method of filtering a fluid containing solids is also disclosed. The method includes flowing the fluid into a first separating means for separating the fluid from the solids and channeling the first cut fluid into an initial settling compartment of a container. Next, the fluid is channeled into a second compartment, with the second compartment containing a plurality of baffle plates. Some of the solids remaining in solution will strike the baffle plates, which in turn will cause the solids to settle to the bottom of the container.
The method further includes conveying the solids to a first discharge pump and discharging the slurry to a second separating means for separating the fluid from the solids, and wherein the solids are further separated from the fluid. Next, the fluid is discharged into the second compartment which in turn will cause the solids to travel through the baffle plates thereby causing the suspended solids to strike the baffle plates. Some of the solids remaining in solution will settle to the bottom of the container and will in turn be conveyed to the first discharge pump. The solids can then be discharged to the second separating means thereby further separating the fluid from the solids. The fluid is exited from the container, and in particular, the fluid stream is exited from the baffle plate compartment.
In one embodiment, the first separating means comprises a linear shaker and the method includes collecting the solids into a bin. Additionally, the second separating means comprises a cyclone separator in tandem with a linear shaker device and the method includes collecting the solids in the bin. The third separating means may comprise a cyclone separator in tandem with a linear shaker means and the method includes collecting the solids into the bin.
In one embodiment, the step of conveying the solids to the first discharge pump includes providing an auger blade placed in the bottom of the container and rotating the auger blade so that the solids are pushed to an inlet for the first discharge pump. The spiral blade can be rotated at a variable speed in order to vary the solids concentration of the slurry to the cyclone separators. In the preferred embodiment, the baffle plates are disposed at an angle of between 45 degrees to 70 degrees. Additionally, the method may further comprise mixing an additive and/or bulk material to the fluid within a mixing compartment. The method may also include suctioning from either the container or mixing compartment and pumping back into the mixing compartment in order to mix the fluid stream with an additive.
An advantage of the present invention includes having a modular design wherein a component of the system may be added or removed from the system. Another advantage is the system may be transported easily from one location to another location. For instance, the frame may be lifted via a crane onto vessels, barges, flat beds, etc. Also, the frame may include wheels so that the entire system can be transported via a vehicle such as a truck.
Another advantage is that the novel system and method will remove solids from 5 microns and larger in some applications. Still yet another advantage is that the system allows for redundancies in that the fluid stream is introduced to multiple separation devices such as the linear shaker, weir, baffles, cyclone separators, settling tanks, etc. Additionally, the fluid stream can be continuously recycled through the system until the desired level of filtration is achieved.
Further, it is desirable to have the solids thus collected to be essentially fluid-free. Another advantage is that the solids thus recovered contain very little in-situ fluid.
A feature of the present invention includes having a linear shaker that separates large diameter solids from the fluid stream. Another feature is the option to use other types of shakers, such as orbital shakers that can also separate small diameter solids from the fluid stream. Yet another feature is the mixing compartment that can be added to the system for the mixing of bulk materials and/or additives to the fluid stream.
Still yet another feature includes use of an auger type of device for conveying the solids to a pump member. In the preferred embodiment, the auger type of device is a spiral blade without the shaft. The speed of the rotation of the auger blade can be varied depending on the nature of the slurry and the desired process rate of the fluid stream. Thus, a feature includes decreasing or increasing the rotation rate of the spiral blade in order to meet processing efficiency goals. Another feature includes use of baffles in a baffle module, with the baffle plates being tilted to maximize the impact of the suspended solids during fluid flow as well as to provide the proper orientation for fluid flow through the container.